Gasoline composition



United States Patent 3,506,416 GASOLINE COMPOSITION Seymour H. Patinkin, Chicago, and Daniel B. Eickemeyer, Park Forest, Ill., assignors to Sinclair Research, Inc., New York, N.Y. a corporation of Delaware No Drawing. Continuation-impart of applications Ser. No. 399,353 and Ser. No. 399,354, both Sept. 25, 1964, and a continuation of application Ser. No. 675,041, Oct. 13, 1967. This application Mar. 4, 1969, Ser. No. 809,459

Int. Cl. Cl N22 US. C]. 44-69 25 Claims ABSTRACT OF THE DISCLOSURE A gasoline composition comprising hydrocarbon gasolines, an antiknock quantity of tetra-lower-alkyl lead compound, and a gasoline soluble metal salt of a hydroxamic acid having the formula:

wherein R is a hydrocarbon radical of up to 30 carbon atoms. The metal is selected from the group consisting of Groups Ia, IIa, IIIa, Va, Ib, IIb, IIIb, IVb, Vb, VIb, VIIb, VIII and tin and a sufiicient amount of the salt is added to provide 0.002 to 0.8 milligram atom of metal per gallon of gasoline.

This application is a continuation-impart of application Ser. No. 399,353, filed Sept. 25, 1964, and application Ser. No. 399,354, filed Sept. 25, 1964, and a continuation of Ser. No. 675,041, filed Oct. 13, 1967, all now abandoned.

The present invention relates to distillate hydrocarbon gasoline compositions which when employed in spark ignition engines lead to improved engine performance.

One of the chief disadvantages attending the use of known additives to lessen abnormal combustion of gasoline in, for instance, automobile engines is that they adversely affect the nature and increase the amount of deposits in the combustion space. These effects manifest themselves in a variety of ways particularly in the case of the higher compression engines. For instance, a fuel having an octane number appropriate to the designed engine compression ratio is unable to give the same antiknock performance after the formation of extensive deposits. To obtain the intended antiknock performance requires a fuel of higher octane number, and this effect has become known as the octane requirement increase or ORI of the engine. Modern engines also evidence a tendency to rumble, an objectionable shuddering noise, apparently caused by flexing of the crankshaft due to deposit-induced abnormal combustion. Surface ignition induced by deposits also often creates abnormalities such as preignition, autoignition and wild ping. Combustion chamber deposits are known to cause piston ring wear and to reduce exhaust valve life. All of these facets of combustion abnormalities can lead to engine damage and/ or loss in power and efficiency.

Various commonly employed gasoline additives as, for example, phosphate compounds such as tricresyle phosphate, cresyl diphenyl phosphate, etc., are known to improve engine operation with respect to certain'of the problems presented by deposit-induced ignition. Relatively large amounts of these compounds are needed, however, to effectively combat the combustion abnormalities, particularly rumble.

It has now been found that leaded gasolines having added thereto about 0.002 to 0.4 or even 0.8 millimole of metal per gallon as a gasoline-soluble metal salt of hydroxamic acids exhibit improved engine performance with respect to one or more of lower octane number requirement increase, improved rumble, surface ignition characteristics, reduced piston ring Wear and extended exhaust valve life. The metal of the hydroxamates of the invention can be a metal of Groups IIIa, Va, Ib, III), 111]), IVb, Vb, VIb, VIIb, VIII, tin or a mixture of two or more of these metals. Among these metals it is preferred to use aluminum, antimony, bismuth, copper, zinc, cadmium, mercury, scandium, titanium, zirconium, vanadium, niobium, chromium, molybdenum, tungsten, manganese, the iron group metals (iron, cobalt and nickel) and tin. Nickel and cobalt are especially preferred. The groups of the Periodic Chart mentioned above are as designated on the inside front cover of the Merck Index, seventh edition, Merck & Co., Inc., Rahway, N.I., 1960. It, has also been found in accordance with a second embodiment that leaded gasolines having added thereto about 0.002 to 0.4 or even 0.8 millimole or milligram atoms of metal per gallon as a gasoline-soluble alkali and alkaline earth metal salt, i.e., Groups Ia and Ila, of hydroxamic acids exhibit improved engine performance with respect to one or more of lower octane number requirement increase, improved rumble, surface ignition characteristics, reduced piston ring wear and extended exhaust valve life. The preferred alkali metal salts are those of sodium, potassium and lithium, and the preferred alkaline earth metal salts are those of calcium, barium and strontium.

As another embodiment, the invention contemplates adding in combination with the first mentioned metal salts, small amounts of alkali metal hydroxamates. Preferred alkali metal hydroxamates are those of sodium, potassium and lithium.

The hydroxamic acids, the salts of which constitute the additives of the invention have the following formula:

II RO-NHOH wherein R is a hydrocarbon radical of up to about or or more carbon atoms on the average, often at least about 4 and preferably about 8 to 18 carbon atoms. R can be an aliphatic aromatic or mixed aliphatic-aromatic radical and is preferably nonoleofinic and nonacetylenic, i.e., having adjacent carbon atoms no closer than 1.40 A. The total number of carbon atoms in a molecule of the hydroxamic acid is preferably up to about or even up to about 30 and the salt of the acid is soluble in the gasoline at least to the extent employed in the invention. Also the salts may contain more or less than the stoichiometric equivalent of the metal and thus the product may contain free hydroxamic acid or when the metal is polyvalent, it may be attached to another group, for instance, the inorganic anion of the compound used to form the hydroxamate salt. Preparation of the salts can be by any method of the art.

The preferred R groups include the straight or branch chained alkyl groups, phenyl and alkyl-substituted phenyl groups whose alkyl substituents contain a total of up to 18 carbon atoms. Illustrative of suitable R groups are pentyl, butyl, octyl, isooctyl, 2-ethyl-heptyl, dodecyl, oleyl, octadecyl, tetradecyl, phenyl, and alkylated phenyls such as cresyl, xylenyl, propyl phenyl, bntyl phenyl, dibutyl phenyl, monoamylphenyl, diamyl phenyl, decyl phenyl, dodecyl phenyl, tetradecyl phenyl, hexadecyl phenyl and octadecyl phenyl.

In order to provide leaded gasolines of further enhanced characteristics, for instance, as to preignition, spark plug fouling and even, in at least some cases, rumble, there can be included in the gasoline composition of the invention a gasoline-soluble, phosphorous compound having the formula:

wherein R has the value described above with respect to the hydroxamic acid from which the metal salts of the invention are made; R is hydrogen or R and n is an integer of to 1. R is preferably an aromatic, e.g. phenyl, hydrocarbon radical of 6 to 12 carbon atoms and can be substituted as, for instance, with lower alkyl groups say of 1 to 4 carbon atoms. Thus, the phosphorous compound can be a mono-, di-, or tri-ester. We also prefer to employ a phenyl, alkyl-phenyl or a mixed phenyl-alkyl phenyl ester of phosphorous. Thus, one or more of the ester groups is preferably an alkyl phenyl radical, often of about 7 to carbon atoms. See US. Patent No. 2,889,212 for a further list of the useful phosphates and phosphites.

These auxiliary phosphate and phosphite additives can be prepared by reacting the appropriate alcohol or aromatic hydroxy compound with phosphoric acid to make the phosphate or with phosphorous trichloride to form the phosphite.

The preferred alcohols are alkanols which can be straight or branch chained and alkyl-substituted phenols whose alkyl substituents contain a total of up to 18 carbon atoms, and preferably are lower alkyl, especially methyl. The aromatic hydroxy compounds and aliphatic alcohols may be substituted with nondeleterious groups. Illustrative of suitable alcohols are pentanol, butanol, octanol, isooctanol, 2-ethyl-hepatnol, dodecanol, oleyl alcohol, octadecyl alcohol, tetradecyl alcohol, alcohols prepared by the 0x0 process, phenol, and alkylated phenols such as cresol, xylenol, propyl phenol, butyl phenol, dibutyl phenol, monoamylphenol, diamyl phenol, decyl phenol, dodecyl phenol, tetradecyl phenol, hexadecyl phenol and octadecyl phenol. Particularly preferred alkyl phenols are ortho, meta and para cresol; 2,4- and 2,5- xylenol; 2,4 dimethyl-6-tertiary butylphenol; octyl and nonylphenols.

By the term leaded gasoline to which the additives of the present invention are incorporated is meant hydrocarbon fractions boiling primarily in the gasoline range, usually about 100 to 425 F., having added thereto a small amount, generally between about 1 to 6 cc. per gallon, preferably about 2 to 4 cos. per gallon, of a termlower-alkyl lead compound as antiknock agent. The gasolines are usually composed of a major amount of a blend of hydrocarbon mineral oil fractions boiling primarily in the aforementioned range and will contain varying proportions of paraflins, olefins, naphthenes and aromatics derived by distillation, cracking and other refining and chemical conversion processes practiced upon crude oil fractions. Straight run gasolines, gasolines derived from cracking gas oil, gasolines or reformate from reforming straight run naphtha over a platinum-alumina catalyst in the presence of hydrogen, etc., are components frequently used in making up a gasoline composition. A typical premium gasoline, besides containing a small amount of a tetra-lower-alkyl lead compound as an antiknock agent may also contain small amounts of other non-hydrocarbon constituents used to impart various properties to the gasoline in its use in internal combustion engines, e.g., halohydrocarbon scavengers, oxidation inhibittors, etc. Such gasolines frequently have a Research Method octane number of about 90 to 105, and a Motor Method octane number of about 80 to 98.

The metal hydroxamate component of the invention is incorporated in the leaded gasoline in small amounts sufficient to provide a composition exhibiting an advantagein-spark-ignition engines, for instance, with respect to one or more of improved rumble surface ignition characteristics, lower octane number requirement increase, reduced piston ring Wear and longer exhaust valve life. The actual amount of the metal salt additive employed may vary depending upon the particular gasoline used, its lead content, etc. In any event sufiicient of the metal salt is employed to supply 0.002 to 0.4 or even 0.8 preferably 0.025 to 0.3, millimole or milligram atom of the metal per gallon of gasoline. The additive will usually provide the gasoline with 0.00004 to 0.008 gram of one or a combination of the metal of the salts per gram of lead, preferably 0.0005 to 0.006 gram of the metal per gram of lead. This often means that about 0.5 to 15 or 30 or more pounds of the metal salt is added, preferably about 2 to 20 pounds, per 1000 barrels of gasoline. The alkali metal hydroxamate, when employed, is ordinarily added in an amount of 0.002 to 0.8 millimole or milligram atoms of metal per gallon of gasoline and the total of a combination of the selected metal hydroxamate and alkali metal hydroxamate is preferably about 0.002 to 0.8 millimole of metal per gallon of gasoline.

When used, about 0.05 to 0.6 theory, preferably about 0.15 to 0.5 theory, of the auxiliary phosphate or phosphite additive, based on the lead content of the gasoline, is generally employed. The term theory as applied to the amount of the phosphorous additive means the amount required to react stoichiometrically with the lead so that all of the lead atoms and all of the phosphorous atoms form 3( 4)2- The following examples are given to illustrate the advantages provided leaded gasolines by the additives of the present invention.

EXAMPLE I Nickel tetradecylhydroxamate, calculated as 10.3% by weight nickel, is added in an amount of 9.4 lbs. of the salt per 1000 barrels to a gasoline composed of 37 volume percent light straight run gasoline, 23 volume percent light catalytically cracked gasoline, 13 volume percent heavy catalytically reformed gasoline and 27 volume percent heavy catalytically cracked gasoline containing 3 cc. per gallon of TEL as Motor Mix (TEL Motor Mix contains 59.2% tetraethyl lead, 13.0% ethylene dibromide, 23.9% ethylene dichloride and 3.9% hydrocarbon diluent dyes, etc.) and 0.2 theory cresyl diphenyl phosphate (CDP).

Evaluation of the resulting composition in a spark ignition engine shows operation of engine to be improved with respect to rumble, surface ignition characteristics, octane number requirement increase, ring wear and exhaust valve life.

Similar results can be obtained by adding to the same gasoline containing TEL Motor Mix and GDP the following additives in the designated amounts:

Amount of Cale. additive percent lbs/1,000 Example Additive metal bbls. gasoline II A1 dodecylbenzene- 1. 89 15, 0

hydroxamate. III Sb hexadecylhydroxamate- 7. 15. 8 IV.. Cu tetradecylhydroxamate. 10. 4 5. V Zn hexadecylhydroxamate- 10. 2 6. 5 VI- Se eicosylhydroxamate 6. 3 7. 4 VIL. Ti hexadecylhydroxamatan. 3. 0 15. 8 VIII Zr oetadecylhydroxamate 5. 8 16. 8 IX V tetradecylhydroxamate- 6.2 8. 5 X Cr docosylhydroxamate 4. 5 12. 0 XI..- Co octadecylhydroxamate-. 8. 6 7. 0 XII Sn dodecylhydroxamate 11. 4 10. 5 XIII. Mn hexadecylhydroxamate. 8. 3 6. 5 Na oetadecylhydroxamate- 6. 8 2 Ni tetradecylhydroxamate- 9. 4 3

EXAMPLE XV Sodium octadecylhydroxamate, calculated as 6.8% by weight sodium, is added in an amount of 3.5 lbs. of the salt per 1000 barrels to a gasoline composed of 37 volume percent light straight run gasoline, 23 volume percent light catalytically cracked gasoline, 13 volume percent heavy catalytically reformed gasoline and 27 volume percent heavy catalytically cracked gasoline containing 3 cc. per gallon of TEL as Motor Mix (TEL Motor Mix contains 59.2% tetraethyl lead, 13.0% ethylene dibromide, 23.9% ethylene dichloride and 3.9% hydrocarbon diluent, dyes, etc.) and 0.2 theory cresyl diphenyl phosphate (CDP).

Evaluation of the resulting composition in a spark ignition engine shows operation of engine to be improved with respect to rumble, surface ignition characteristics, octane number requirement increase, ring wear and exhaust valve life.

EXAMPLE XVI Similar results can be obtained by adding to the gasoline composition of Example I calcium hexadecylhydroxamate (calculated as 6.5% Ca) in an amount of 6.4 lbs/1000 barrels of gasoline.

The OR]: of an engine is obtained by the following procedure:

After determining the clean or initial octane requirement of a 327-cubic-inch 10.021 compression ratio engine, the gasoline without the additive of the invention is run for 216 hours and the octane requirement increase noted. The engine is then thoroughly cleaned of all deposits so that it again exhibits the same clean octane requirement and run on an identical cycle, with the same gasoline but containing the additive of the invention. After 216 hours use, the octane requirement increase is noted and compared with the octane requirement increase found with the gasoline without the additive to determine the extent of improvement.

The rumble tendency of an engine after a given time of use is measured by aLIB number. The number represents the percent isooctane (containing 3 cc. TEL/gallon) required in a blend with benzene (containing 3 cc. TEL/gallon) after a given period of engine operation using the fuel under test, to avoid rumble at a given r.p.m., e.g. 2,000 r.p.m. The test procedure comprises stopping the gasoline to the engine at any given period of engine operation and employing as a fuel to the engine a fuel containing a certain percent of isooctane in an isooctane-benzene blend (containing 3 cc. TEL/gallon), manually opening the throttle at a given rate and recording the r.p.m. at which rumble occurs, if any in fiat occurs. The faster one is able to run the engine with the lowest percent of isooctane in the blend the better the rumble resistance of the engine. Thus, the lower the LIE number the better the rumble characteristics of the engine. The gasoline with and without the additive of the invention is tested in this manner and the LIB numbers obtained with each are compared.

The piston ring wear is determined by equipping a single cylinder COT engine with radioactive rings installed in the grooves of the pistons. The lubricating oil system of the engine is provided with asealed monitoring well which contains a scintillation counter. The ring wear rate is determined by passing the lubricating oil through the monitoring well and therein detecting the concentration in mg./hour of radioactive iron trans ported to the oil due to wear of the piston rings.

The test to determine the effect of the fuel composition on exhaust valve life involves running an automobile engine at a fixed number of hours at constant or varied speeds and loads depending on the engine used and then noting the number of valves that failed during this period of time.

The test used to determine the deposit-induced ignition characteristics of the fuel composition comprises equipping an engine with an L-head cylinder and an electronic wild ping counter which records the total number of wild pings which have occurred during the test pe riods. Since deposit-induced ignition is the tendency to ignite the fuel-air mixture erratically and to produce unconrolled combustion noticeable as, for instance, wild ping, the electronic counter which is used in conjunction with an ionization gap, automatically detects and records uncontrolled combustion.

It is claimed:

1. A gasoline composition consisting essentially of hydrocarbon gasoline, an antiknock quantity of tetra-loweralkyl lead compound, and a gasoline-soluble metal salt of a hydroxamic acid having the formula:

RC-NHOH wherein R is a hydrocarbon radical of up to 30 carbon atoms, said metals is selected from the group consisting of Groups Ia, IIa, IIIa, Va, Ib, IIb, IIIb, IVb, Vb, VIb, VIII), VII and tin, the amount of said metal salt being sufficient to provide 0.002 to 0.8 milligram atom of selected metal of said salt per gallon of gasoline.

2. A gasoline composition consisting essentially of hydrocarbon gasoline, an antiknock quantity of tetra-loweralkyl lead compound, and a gasoline-soluble metal salt of a hydroxamic acid having the formula:

II RC-NHOH wherein R is a hydrocarbon radical of up to about 30 carbon atoms on the average, R is selected from the group consisting of hydrogen and R, and n is an integer having a value of 0 to 1.

4. The composition of claim 2 wherein the metal is an iron group metal.

5. The composition of claim 4 wherein the metal is nickel.

6. The composition of claim 3 wherein at least one R in the structure of claim 3 is an alkyl phenyl radical of 7 to 15 carbon atoms.

7. The composition of claim 6 wherein the amount of phosphorous compound is about 0.15 to 0.5 theory.

8. The composition of claim 6 wherein the selected metal is an iron group metal.

9. The composition of claim 6 wherein the metal is nickel.

10. A gasoline composition consisting essentially of hydrocarbon gasoline, an antiknock quantity of a tetralower alkyl lead compound, and a gasoline soluble metal salt of a hydroxamic acid having the formula:

wherein R is a hydrocarbon radical of up to 30 carbon atoms, said metal is selected from the group consisting of Groups Ila, Va, Ib, IIb, IIIb, IVb, Vb, VIb VIIb, VIII and tin, the amount of said metal salt being sufficient to provide about 0.025 to 0.3 milligram atom of selected metal per gallon of said gasoline.

11. The composition of claim 9 in which there is also included about 0.05 to 0.6 theory of a gasoline soluble phosphorous compound having the formula:

R'0\ on )1 RO 0 wherein R is a lower alkyl phenyl radical of 7 to 15 carbon atoms and R is selected from the group consisting of phenyl and R.

12. The composition of claim 11 wherein the selected metal is an iron group metal.

13. The composition of claim 12 wherein the metal is nickel.

14. The composition of claim 13 wherein the phosphorous compound is cresyl phosphate.

15. The composition of claim 13 to which is added 0.002 to 0.8 milligram atom of gasoline soluble alkali metal salt of hydroxamic acid.

16. A gasoline composition consisting essentially of hydrocarbon gasoline, an antiknock quantity of tetralower-alkyl lead compound, and a gasoline soluble metal salt of a hydroxamic acid having the formula:

6 RO-NHOH wherein R is a hydrocarbon radical of up to 30 carbon atoms, the metal of said salt being selected from the group consisting of alkali and alkaline earth metals and the amount of said metal salt being sufiicicnt to provide 0.002 to 0.8 milligram atom of metal per gallon of gasoline.

17. The composition of claim 16 in which there is also included about 0.05 to 0.6 theory of a gasoline soluble phosphorous compound having the formula:

wherein R is a hydrocarbon radical of up to about 30 carbon atoms on the average, R is selected from the group consisting of hydrogen and R, and n is an integer having a value of to 1.

18. The composition of claim 17 wherein at least one R in the structure of claim 17 is an alkyl phenyl radical of 7 to carbon atoms.

19. The composition of claim 18 wherein the amount of phosphorous compound is about 0.15 to 0.5 theory.

20. The composition of claim 16 wherein the metal is an alkali metal.

21. The composition of claim 16 wherein the metal is an alkaline earth metal.

22. A gasoline composition consisting essentially of hydrocarbon gasoline, an antiknock quantity of a tetralower-alkyl lead compound, and a gasoline soluble metal salt of a hydroxamic acid having the formula:

i RO-NHOH wherein R is a hydrocarbon radical of up to carbon atoms, the metal of said salt being selected from the group consisting of alkali and alkaline earth metals and the amount of said metal salt being suflicient to provide about 0.025 to 0.3 milligram atom of selected metal per gallon of said gasoline.

23. The composition of claim 22 in which there is also included about 0.05 to 0.6 theory of a gasoline soluble phosphorous compound having the formula:

RO OR RO/ \O wherein R is a lower alkyl phenyl radical of 7 to 15 carbon atoms and R is selected from the group consisting of phenyl and R.

24. The composition of claim 23 wherein the metal is an alkali metal.

25. The composition of claim 24 wherein the phosphorous compound is cresyl diphenyl phosphate.

References Cited UNITED STATES PATENTS 2,560,542 7/1951 Bartleson et a1. 4469 2,737,932 3/1956 Thomas 4466 X 2,834,662 5/ 1958 Hirschler et al 4469 X 2,834,663 5/1958 Hinkamp et a1 4469 X 2,834,664 5/1958 Irish et al. 4476 X 2,889,212 6/1959 Yust et al. 4469 3,041,154 6/1962 Sandy et a1 4470 X 3,065,065 11/1962 Sutton et al. 44-69 DANIEL E. WYMAN, Primary Examiner W. J. SHINE, Assistant Examiner US. Cl. X.R. 4468, 71

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,506J416 Dated April 1 4, 1970 Inventor(s) Seymour H. Patinkin and Daniel B. Eickemeyer It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In Claim 3, there should be a double bond between the phosphorus atom and O Claim 10, Line 59 thereof, delete "11a" and insert therefor --IIIa-.

Claim 1 L, Line 2 thereof, immediately after "cresyl" insert --dipheny1--.

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